/*
 	Tool for Path Finding Algorithm Testing (ToPFAT) 
 	
    Copyright (C) 2009, Teemu Turunen and Arttu Viljakainen 
    Published under GNU General Public License V3 
    (see http://www.gnu.org/licenses/licenses.html)
    
    This file is part of Tool for Path Finding Algorithm Testing.

    Tool for Path Finding Algorithm Testing is free software: you can 
    redistribute it and/or modify it under the terms of the GNU General 
    Public License as published by the Free Software Foundation, 
    either version 3 of the License, or (at your option) any later version.

    Tool for Path Finding Algorithm Testing is distributed in the hope that it
    will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General 
    Public License for more details.

    You should have received a copy of the GNU General Public License
    along with Tool for Path Finding Algorithm Testing. If not, see         <http://www.gnu.org/licenses/>.
 */

package algorithms.astar.heuristics;

import algorithms.astar.Node;

/**
 * Interface for different H cost heuristics.
 * For more about A* heuristics, see A* tutorials for more information.
 * 
 * @author teturun
 *
 */
public interface HCostHeuristic {

	/**
	 * Calculates H cost according to used heuristic.
	 * For more about A* heuristics, see A* tutorials for more information.
	 * 
	 * @param start Node to which H cost is calculated
	 * @param goal Node that algorithm tries to reach
	 * @return H cost
	 */
	public abstract int calculateCost(Node start, Node goal);
	public abstract String toString();
}
